Terminology, reference = 5 (= 5 x 1/8 = 5/8") B = British Standard,
-1 = Simplex (one row of teeth)
Last 2 numbers denote number of teeth
e.g. 51.38 = 5/8 pitch, Simplex, 38 Tooth Sprocket
To suit British Standard Roller chain :-
10B-1 (B.S. Reference), 110056 (Renold), 5SR (Morse)
